The present invention relates to a vertical impact system, and in particular to a resonantly driven system for breaking up a pavement surface using a specially adapted pavement breaking tool.
A variety of different pavement breaking and other types of surface impact tools are in use at the present time. Typically, such tools employ a heavy weight which is lifted and allowed to fall to provide the power stroke of the tool. Lifting of the weight for each stroke is generally inefficient, but more efficient solutions have not been available to date where large forces are necessary. Pneumatic and hydraulic tools are often used, but such tools are limited as to the amount of force that can be applied because the reaction forces on the tool are equal to those applied to the surface.
In the patent literature, the patent to Gettelman, U.S. Pat. No. 1,841,802, discloses a pick or tamping tool located at the end of a leaf spring supported at its center. This flexible spring, however, is insufficient to generate sufficiently large forces to break up most pavement, or provide a sufficient tamping action. Also, the large amplitudes involved render the device hard to control, and applicant has no knowledge that the Gettelman device has ever been successfully applied in practice.
Theoretical advantages in using resonant systems to apply large forces have been disclosed in the patent literature, as illustrated in U.S. Pat. Nos. 3,232,669 and 3,367,716, to Bodine. However, such resonant techniques apparently have not been successfully applied to vertical impact tools such as the type disclosed herein.